webpack dynamic import not working

Node.js version: 8.11.3 By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. If you think this is still a valid issue, please file a new issue with additional information. - Coco Jun 21, 2018 at 20:36 Already have this plugin installed, and it still does not work. eg: ./locale. The problem is if you want to dynamically load a file, in this case, an image, Webpack by default generate a chunk for that module, something similar to this: The big issue with that is when you request dynamic imported images, it will do a network request to get the chunk and then another one to get the image, adding unnecessary overhead to your app. webpackPreload: Tells the browser that the resource might be needed during the current navigation. What is the !! @ooflorent Is it possible to import the bundle from external url in webpack for e.g. A link for the above diagram can be found here. Removing values from this cache causes new module execution and a new export. How can we prove that the supernatural or paranormal doesn't exist? Using docker volume properly will lead to higher productivity. Connect and share knowledge within a single location that is structured and easy to search. to your account, I made a vue component package my-custom-comp, which contains dynamic import: Then I started going through all of the plugins in the Babel configuration. // Here the animal name is written by the user. Find centralized, trusted content and collaborate around the technologies you use most. Webpack and Dynamic Imports: Doing it Right | by Rubens Pinheiro This means I need to dig deeper into Babel Configuration. How do you ensure that a red herring doesn't violate Chekhov's gun? - A preloaded chunk has medium priority and instantly downloaded. Just an update for those going down this path: If you are using React, I would recommend react-loadable, makes it extremely easy to do dynamic imports on a per-component basis a lot of large companies use it. fish.js Dynamic Import from external URL will throw Module not found error. Similar one works for me ( not exactly the same version of Webpack though ), Try to add one more comment to force code splitting. Version: webpack 4.28.2 The compiler ensures that each dependency is available. Sign up for a free GitHub account to open an issue and contact its maintainers and the community. Therefore a cache in the runtime exists. Although it worked with webpack@3. You can also subscribe to our weekly newsletter at http://frontendweekly.co, import(`assets/images/${imageName}.jpg`).then( src => ), is better to break the big bundles in smaller pieces. Dynamic Import from external URL will throw `Module not found` error The map's keys are the IDs of the chunks and the values depend on the chunk's status: 0(when the chunk is loaded), Promise(when the chunk is currently loading) and undefined(when the chunk hasn't even been requested from anywhere). But I can't get it to work. If the current behavior is a bug, please provide the steps to reproduce. In this case, having only a responsive design doesnt cover what you want, so you build a page renderer which loads and renders the page based on the user platform. Now here's the part that errors on build. As we can control the loading strategy, we can also use the magic comments to control the generated chunk names too by simply doing this: Instead of numbers, Webpack will use the chosen names to the generated chunks. Time: 2813ms By adding comments to the import, we can do things such as name our chunk or select different modes. In the previous section we've seen how to manually specify the mode, so the way to tell webpack we want to use the lazy-once mode should come as no surprise: The behavior in this case is somehow similar to what we've encountered in the previous section, except that all the modules which match the import's expression will be added to a child chunk and not into the main chunk. Dynamic import from node_modules is not working #8934 - GitHub // Here the user chooses the name of the file. Currently, @babel/preset-env is unaware that using import() with Webpack relies on Promise internally. The interesting thing is that if now the user requires a different module which also belongs to the just loaded chunk, there won't be any additional requests over the network. I solved it. hey @sowinski, because that's an external script, you can't import it and access its contents directly. True, even if were dynamic loading the components, this stills a pretty attached solution. React.lazy handles this promise and expects it to return a module that contains a default export React component. Connect and share knowledge within a single location that is structured and easy to search. Then I came across a comment in one of the web packs repo: After struggling for a few minutes and a few trials and errors, I realized that I dont need to configure comments in babel configuration. React Lazy This React component is a function that takes another function as an argument. anytime.bundle.js 109 KiB 0 [emitted] anytime I don't know if there's a cleaner way, but I've seen script.js used with success for the google maps api specifically. Here's the function which calls the dynamic import: Everything I have read says this is the way to set this up. Also I am using the svg-inline-loader. Flask api hosted as a docker container works with localhost:5000 but not with 172.17..2:5000; Python Flask heroku application error; Failed to compute cache key: "/films" not found: not found? In this article, we will dive deep into the concept of dynamic expressions when it comes to the import function and hopefully, at the end, you will be more acquainted with the range of possibilities that this webpack's feature provides. Hey, I noticed that Webpack just put numbers to generated chunks. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. // Requesting the module that should already be available. Modules are reusable chunks of code built from your app's JavaScript, node_modules, images, and CSS styles, which are packaged to be easily used on your website. The import() must contain at least some information about where the module is located. In this way, you only load the code that you need. We hand-pick interesting articles related to front-end development. Adding Hashes to Filenames - SurviveJS If I want to use the cat module, after clicking on the button, I should see a new request for the chunk which contains the module in question: As probably noticed, the console tells us that the chunk has been loaded, as well as the module it contains, namely the cat module. This issue had no activity for at least three months. Is it suspicious or odd to stand by the gate of a GA airport watching the planes? Version 2 of webpack supports ES6 module syntax natively, meaning you can use import and export without a tool like babel to handle this for you. They are capable of bundling your app and generating your bundle chunks, and especially lazy loading them, so you can load only the one that you need at a given time. Dynamic import seems to be the solution but Im not having any luck getting webpack to create the chunk files. Vue.js dynamic image src with webpack require() not working you are just linking to stuff outdated links. When the asset's content changes, [contenthash] will change as well. just load them when used. Precisely, webpack stores the loaded chunks in a map such that if the chunk that is requested has already been loaded, it will be immediately retrieved from the map. Module Methods | webpack Special thanks Max Koretskyi for reviewing this article and for providing extremely valuable feedback. See the spec for more information and import() below for dynamic usage. Underlying modules can then be easily resolved later on: If mode is set to 'lazy', the underlying modules will be loaded asynchronously: The full list of available modes and their behavior is described in import() documentation. node --max_old_space_size=8000 scripts/start.js. Successfully merging a pull request may close this issue. A normal import statement cannot be used dynamically within other logic or contain variables. This section covers all methods available in code compiled with webpack. [38] ./sources/styles/anytime.css 39 bytes {0} [built] If you find this article helpful, please share it with others ? to your account, __webpack_require__ is called with result of promise external when it's is loaded as dynamic import, which results with error - A preloaded chunk starts loading in parallel to the parent chunk. Is there a single-word adjective for "having exceptionally strong moral principles"? Dynamic Imports of JSON - DEV Community If youre using HTTP2 is better to break the big bundles in smaller pieces. It's totally understandable that webpack is a bundler and it should not take care of loading script from another domain. You signed in with another tab or window. I cant figure out what in my setup is failing. Split out the given dependencies to a separate bundle that will be loaded asynchronously. Ive tried several different variations of the imports. For a full list of these magic comments see the code below followed by an explanation of what these comments do. This feature relies on Promise internally. The compiler will ensure that the dependency is available in the output bundle. Making statements based on opinion; back them up with references or personal experience. Already on GitHub? Now it works. The diagrams have been made with Excalidraw. Otherwise, an error will be thrown. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. webpack it threating resolved value as module id with dynamic imports witch results with. When using the eager mode, there won't be any additional chunks created. Due to the dynamic nature of JavaScript, webpack can't easily determine which exports will be used, so webpack . A prefetched chunk is downloaded in browser idle time. 7 comments LASkuma commented on Nov 5, 2018 edited webpack-bot added the inactive label on May 31, 2019 alexander-akait closed this as completed on May 31, 2019 colscott mentioned this issue on Jun 16, 2019 For instance: In the above map(which can be found in the dist/main.js file - the only generated file), it is known for sure that the cat module is used across the app. All the modules which match the import's pattern will be part of the same main chunk. { type:"header", template:"Dynamically imported UI" }. When webpack finds a dynamic import, it will assume that code should be code split and lazy loaded. As a smart developer, you dont want to load the entire code for desktop if the user is on mobile, and vice versa. Thanks for contributing an answer to Stack Overflow! By using weak imports, we're essentially telling webpack that the resources we want to use should already be prepared for retrieval. Keep in mind that you will still probably need babel for other ES6+ features. Using the webpackInclude and webpackExclude options allows you to add regex patterns that reduce the number of files that webpack will bundle for this import. We can notice from this diagram the 4 chunks that have been created(one for each file in the animals directory), along with the main parent chunk(called index). dog.js Suppose there is a directory structure that looks like this: By using the import function in our application code: webpack will generate a chunk for each file in the animals directory. Similar to require.ensure, this will split the given dependencies into a separate bundle that will be loaded asynchronously. Does anyone yet has found a solution? Thereby I reduced the loading time to one minute. A prefetched chunk starts after the parent chunk finish. Available since webpack 5.0.0-beta.18. https://github.com/webpack/webpack/issues/5857#issuecomment-338118561, GitHub - airbnb/babel-plugin-dynamic-import-webpack: Babel plugin to transpile import() to require.ensure, for Webpack, Babel is configured to NOT remove the comments. Actually webpack would enforce the recommendation for .mjs files, .cjs files or .js files when their nearest parent package.json file contains a "type" field with a value of either "module" or "commonjs". Consider the following example: The StackBlitz app for this example can be found here. Asking for help, clarification, or responding to other answers. Keep in mind that you will still probably need babel for other ES6+ features. Although it is a popular selling point of webpack, the import function has many hidden details and features that many developers may not be aware of. However, it does not necessarily guarantee that the cat module is available. Check out the guide for more information on how webpackPreload works. Other relevant information: At run time, when the variable language has been computed, any file like english.json or german.json will be available for consumption. Built at: 02/04/2019 6:39:47 AM [8] ./sources/views/timeclock/win_userdepts.js 3.39 KiB {0} [built] Lets suppose you have an app that has different behavior and visuals in some features for mobile to desktop. If the name of the animal can't be found in the animals directory, an error will be thrown. Ive setup my code according to the jet-demos example and still not having any luck with webpack generating the chunk file. The given expression can have multiple dynamic parts. This Is Why fatfish in JavaScript in Plain English It's 2022, Please Don't Just Use "console.log" Anymore Jesse Langford in Better Programming Consolidate Your TypeScript Imports With index.ts Files Help Status Writers Blog According to the document: I should upload dist files of my-custom-comp to cdn or copy dist files of my-custom-comp to app's assets folder? Please pay attention to these enforcements before you read on: Version 2 of webpack supports ES6 module syntax natively, meaning you can use import and export without a tool like babel to handle this for you. This CANNOT be used in an asynchronous function. Sign in Old solution A solution is to use node --max_old_space_size=8000 scripts/start.js to get it working. Have a question about this project? This concept of a map which is used to keep track of modules and their traits is used regardless of the mode we're using. Where does this (supposedly) Gibson quote come from? By clicking it, the chunk will be fetched and the cat module will become accessible and that is because when a chunk is loaded, all of its modules will become available for the entire application. All the following sections will be based on the same example where there is a directory called animals and inside there are files that correspond to animals: Each examples uses the import function like this: import('./animals/${fileName}.js'). // Do something when module is available // Do something when module was loaded before // You can perform dynamic resolves ("context"). Use webpackPrefetch: true magic comment with webpackChunkName . How to resolve dynamic import from node_modules? Sign up for a free GitHub account to open an issue and contact its maintainers and the community. Now it works. The example this section is based on can be found here(make sure to also start the server). So now I am using this fetch library, which was already included in the config (generated by create-react-app after ejecting) Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2. Let's solve solution for this, @Miaoxingren reproducible repo still has the problem? Child mini-css-extract-plugin node_modules/css-loader/index.js!node_modules/less-loader/dist/cjs.js!sources/styles/anytime.css: Webpack and Dynamic Imports: Doing it Right | by Rubens Pinheiro Gonalves Cavalcante | Frontend Weekly | Medium 500 Apologies, but something went wrong on our end. There is no option to provide a chunk name. Working with modern JS you often see static imports for modules: import myLib from './myLib'; But dynamic imports aren't grabbed from the server until runtime. And consider adding service workers with a good caching strategy. - jeron-diovis Feb 8, 2019 at 8:41 Add a comment 2 Answers Sorted by: 6 I was facing the same issue the fix was: 5 comments Contributor roblan commented on Jul 17, 2020 edited roblan changed the title webpack-bot added the Send a PR label chenxsan mentioned this issue try to fix #11197, but failed #11200 Nothing elaborate until now, it's just what we've been doing in other sections, namely specifying the mode we want the import function to operate, which in this case is weak. ), Yeah there really seems something wrong here. Setting TypeScript For Modern React Projects Using Webpack You also need to know that fully dynamic statements such as import (pathToFile) will not work because webpack requires at least some file location information. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Dynamic Import . From this list of plugins, the only plugin that might be the culprit is dynamic-import-webpack, A small plugin to make dynamic imports i.e. Whats the grammar of "For those whose stories they are"? reactjs ComponentA myComponents ComponentA adsbygoogl Thanks for contributing an answer to Stack Overflow! Check out the guide for more information on how webpackPrefetch works. Sign in This feature relies on Promise internally. If Magic Comments (or Any Comment) are not reaching the webpack, then they are lost in the transpiling process. Vivek Kumar Jha on LinkedIn: #webpack @Miaoxingren Please create minimum reproducible test repo. [11] ./sources/views/timeclock.js 2.92 KiB {0} [built] See this thread to the problem https://github.com/webpack/webpack/issues/5747. Thank you for looking at this maksim. The tools that provide this kind of features are: RequireJS, SystemJS, Webpack, Rollup and curl. The value here can be anything except a function. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, Using a library like axios and putting the SVGs in the public folder is a solution but I think it's really not the recommended way, the link ( Adding asssets outside of the module system ) doesn't lead to the explanation anymore :<. The public folder is useful as a workaround for a number of less common cases: You have thousands of images and need to dynamically reference their paths. Lets check it on the code below: But hey, this is a pretty simplist approach. Multiple requires of the same module result in only one module execution and only one export. The [contenthash] substitution will add a unique hash based on the content of an asset. ? Subscribe to the blog to receive new posts right to your inbox. Entrypoint mini-css-extract-plugin = * It takes all of the code from your application and makes it usable in a web browser. [40] ./sources/views sync ^\.\/.$ 1.62 KiB {0} [optional] [built] This is the same for core-js@2, except the imports paths are slightly different: --save-dev @babel/plugin-syntax-dynamic-import, --dev @babel/plugin-syntax-dynamic-import, babel --plugins @babel/plugin-syntax-dynamic-import script.js, Working with Webpack and @babel/preset-env. Because foo could potentially be any path to any file in your system or project. Recovering from a blunder I made while emailing a professor. This is the lazy option's behaviour. Webpack 4 course - part eight. Dynamic imports with prefetch and Moving the files I wanted to import outside of the views folder worked. How to check whether a string contains a substring in JavaScript? As you are using [contenthash] in the output file names, only the changed modules will be cached again by service workers, not all the files. Why are Suriname, Belize, and Guinea-Bissau classified as "Small Island Developing States"? To learn more, see our tips on writing great answers. Basically, this technique ensures that certain modules are only loaded when they are required by the users. 'data:text/javascript;charset=utf-8;base64,Y29uc29sZS5sb2coJ2lubGluZSAxJyk7', 'data:text/javascript;charset=utf-8;base64,ZXhwb3J0IGNvbnN0IG51bWJlciA9IDQyOwpleHBvcnQgY29uc3QgZm4gPSAoKSA9PiAiSGVsbG8gd29ybGQiOw=='. Using Webpack and the dynamic import structure it creates a promise that will retrieve the chunk at runtime and allow you to act on it at that point. In order to quickly mitigate this issue, we can add an import * as c from './animals/cat'; statement at the beginning of the file: If we run npm run build and npm run start again and take the same steps, we should see that the cat module has been successfully executed. To learn more, see our tips on writing great answers. This is the default mode, meaning that you don't have to explicitly specify it. ? // variable will be executed and retrieved. webpack version: 4.28.4 Caching | webpack Webpack Bundler , . This will cache the Files on Browser and avoid problems related to Chunks not found (Chunk loading failed) with multiple deploys. This can be verified in our example: after starting the server, try to require any of the modules present in the animals directory. So, to make it work with webpack you need to first install the babel-plugin-syntax-dynamic-import . Refresh the page, check Medium 's site status, or find something interesting to read. Webpack Babel. Redoing the align environment with a specific formatting, How to handle a hobby that makes income in US, Minimising the environmental effects of my dyson brain. Demistifying webpack's 'import' function: using dynamic arguments When using webpack to bundle your application, you can pick from a variety of module syntax styles including ES6, CommonJS, and AMD. As the import is a function receiving a string, we can do powerful things like loading modules using expressions. How can I remove a specific item from an array in JavaScript? What is the expected behavior? I was trying to optimize the React App and as we already have splitChunks in our webpack configuration, it was for granted to pay more attention to code splitting. An in-depth perspective on webpack's bundling process, Change detection and component trees in Angular applications, Improve page performance and LCP with NgOptimizedImage, Deep dive into the OnPush change detection strategy in Angular, Deep dive into the infamous ExpressionChangedAfterItHasBeenCheckedError inAngular, From zone.js to zoneless Angular and back how it all works. So, is better to preload that small image chunks than add it to the bigger bundle/chunk right? What am I doing wrong? See how to Fix it and Tips to avoid related problems. index.js /* webpackChunkName: 'animal', webpackMode: 'lazy-once' */, // Here the user types the name of the module, // Here that module is retrieved directly if possible, otherwise, /* webpackChunkName: 'animal', webpackMode: 'weak' */. This earticle explores the mechanics of the ExpressionChangedAfterItHasBeenCheckedError and brielfly discusses some common setup that lead to the error, Explore the mechanism behind automatic change detection in Angular with zone.js and use cases when to jump in and out of Angular zone. How do I remove a property from a JavaScript object? Is it possible to make webpack search this file from node_modules? It is recommended to treat it as an opaque value which can only be used with require.cache[id] or __webpack_require__(id) (best to avoid such usage). (not not) operator in JavaScript? my-custom-comp.vue, I have my-custom-comp package installed in my app, and add package path to resolve.modules: Disconnect between goals and daily tasksIs it me, or the industry? I am having same problem even with webpack 5, // Uncaught (in promise) Error: Cannot find module 'x' at lib lazy ^. The same steps are taken if we want to use, for instance, the fish module: And the same will happen for each file which matches the pattern resulted in the import function. Let's call your projects Lib (your React component library) and App (the library consumer). Now if we want to use the lion module, I should not see a new request, but only a confirmation that the lion module has been executed: Here's a diagram to supplement what's been accumulated so far: We've saved this section until last because of its peculiarities. require.resolveWeak is the foundation of universal rendering (SSR + Code Splitting), as used in packages such as react-universal-component. Styling contours by colour and by line thickness in QGIS. [37] ./sources/anytime.js 2.12 KiB {0} [built] Finally I fixed this by setting __webpack_public_path__ webpack setting. A prefetched chunk can be used anytime in the future. However, this support does not work with dynamic import() Workaround. Secure websites are necessary requirements. Let's learn how to enable HTTPS on localhost for a PHP application on Apache by Dockerizing it. @babel/plugin-syntax-dynamic-import Babel I can build the jet-demos project files and the bundle files are created in /codebase/. Not the answer you're looking for? "Dynamic" Dynamic Imports Throughout the article we will be using live examples(all of them in the form of a StackBlitz app) and diagrams, so let's get started! Lets refactor our function: - Still not good! Use require instead, e.g. A curious software developer with a passion for solving problems and learning new things. You do not need to add curly brackets.